Method of use for debris removal system for power tool

ABSTRACT

A method of using a hand-held power tool having a debris removal attachment is provided. The method includes providing a hand-held power tool having an output shaft and selectively coupling an extension shaft to the output shaft. The method also includes coupling a first impeller to the extension shaft and providing a housing adjacent the first impeller. The method further includes rotating the first impeller to generate a pressure differential sufficient to draw debris into the housing. The extension shaft has a first end and a second end, the first end configured to couple to the output shaft of the hand-held power tool, and the second end configured to couple to a tool bit.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.12/633,582, filed Dec. 8, 2009, which claims priority to and the benefitof U.S. Provisional Patent Application No. 61/121,076, filed Dec. 9,2008, both of which are incorporated herein by reference in theirentireties.

BACKGROUND

The present disclosure relates generally to the field of hand-held powertools. More specifically, the present disclosure relates to hand-heldpower tools that include systems for collecting or otherwise removingdebris (e.g., particles, dust, sawdust, chips, etc.) generated duringoperation of the hand-held power tools.

Hand-held power tools, such as rotary cutout or cutting tools, generallyinclude a housing and an electric motor contained within or at leastpartially enclosed by the housing. The motor is configured to move atool bit or other cutting accessory at high speeds to form cuts in aworkpiece (e.g., a piece of wood, drywall, tile, etc.). For example, arotary cutting tool such as that disclosed in U.S. Pat. Nos. 5,813,805and 6,443,675 to Kopras et al. (the disclosures of which areincorporated by reference herein in their entirety) is configured torotate a helical or spiral cutting tool bit that includes a sharpcutting edge wrapped in a helix around the longitudinal axis of the bit.According to this example, the rotary cutting tool forms cuts in aworkpiece by moving the tool in a direction that is substantiallyperpendicular to the axis of rotation of the tool bit (i.e., the rotarycutting tool is arranged substantially normal to the workpiece surfaceand moved parallel to the surface of the workpiece to allow the edges ofthe tool bit to remove material from the workpiece).

Hand-held power tools are known to generate a substantial amount ofdebris while cutting. Such debris may interfere with further cutting byaccumulating on the workpiece, on the tool bit, and/or within thecutting tool itself. Such debris may also become airborne and bedispersed throughout the working environment. This may be particularlyundesirable if the hand-held power tool is being used in a “clean”environment, such as within a finished room (e.g., decorated, furnished,carpeted, etc.) since additional cleanup may be necessary.

Some power tools employ vacuum systems connected to the tool to removecutting debris. Such vacuum systems typically make use of an adapterthat has to be connected to an external or standalone vacuum system(e.g., a shop vacuum, etc.) via a vacuum hose or conduit. Thus, use ofsuch an adapter requires a user to obtain a standalone vacuum system.Further, requiring a hand-held power tool to be coupled to a standalonevacuum system often makes use of the hand-held power tool morecumbersome. For example, the vacuum conduit coupling the adapter to thestandalone vacuum system may interfere with the mobility or range of useof the tool. Further, the vacuum conduit may disrupt the balance or feelof the tool for a user.

Some power tools employ vacuum systems which are integrally formed withthe power tool. Such vacuum systems may increase the overall size andweight of the power tools. As can be appreciated, a user is likely touse a hand-held power tool for both applications in which a vacuumsystem would be desirable and applications in which a vacuum systemwould be unnecessary.

Thus, there is a need for a power tool having a debris removal systemthat is not required to be connected to a standalone vacuum system.There is also a need for a power tool having a detachable debris removalsystem that may be securely coupled to the power tool in a relativelysimple and efficient manner. There is also a need to provide a powertool that includes a debris removal system configured to reduce theamount of debris entering the motor housing of the power tool. There isalso a need for a power tool that includes a debris removal system thatis driven by an already existing output shaft of the power tool.

It would be desirable to provide a power tool and/or a debris removalattachment that provides one or more of these or other advantageousfeatures as may be apparent to those reviewing this disclosure. Theteachings disclosed extend to those embodiments which fall within thescope of the appended claims, regardless of whether they accomplish oneor more of the above-mentioned needs.

SUMMARY

One exemplary embodiment relates to a method of using a hand-held powertool having a debris removal attachment. The method includes providing ahand-held power tool having an output shaft and selectively coupling anextension shaft to the output shaft. The method also includes coupling afirst impeller to the extension shaft and providing a housing adjacentthe first impeller. The method further includes rotating the firstimpeller to generate a pressure differential sufficient to draw debrisinto the housing. The extension shaft has a first end and a second end,the first end configured to couple to the output shaft of the hand-heldpower tool, and the second end configured to couple to a tool bit.

Another exemplary embodiment relates to a method of using a hand-heldpower tool having a debris removal attachment. The method includesproviding a hand-held power tool and providing a debris removalattachment. The hand-held power tool includes a motor disposed in amotor housing and an output shaft coupled to the motor. The debrisremoval attachment includes an extension shaft having a first end and asecond end, the second end configured to couple to a tool bit, a firstimpeller coupled to the extension shaft, the rotation of which isconfigured to generate a pressure differential sufficient to draw debrisinto the debris removal system, a housing substantially disposed aboutthe first impeller, a second impeller coupled to the extension shaft,and a substantially planar member separating the first impeller and thesecond impeller. The method further includes detachably coupling thefirst end of the extension shaft to the output shaft.

Another exemplary embodiment relates to a method of using a debrisremoval attachment for a hand-held power tool. The method includesproviding an extension shaft, coupling a first impeller to the extensionshaft, providing a housing adjacent the first impeller, providing alabyrinth seal in a pathway between an exterior of the housing and aninterface of the extension shaft and the output shaft, selectivelycoupling the first end of the extension shaft to an output shaft, androtating the first impeller to generate a pressure differentialsufficient to draw debris into the housing. The extension shaft has afirst end and a second end, the first end configured to couple to anoutput shaft, and the second end configured to couple to a tool bit. Thelabyrinth seal has a plurality of spaced apart annular projectionsprovided for disrupting the pathway.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hand-held power tool according to anexemplary embodiment.

FIG. 2 is another perspective view of the hand-held power tool shown inFIG. 1.

FIG. 3 is a perspective view of a debris removal system according to anexemplary embodiment shown coupled to the hand-held power tool shown inFIGS. 1 and 2.

FIG. 4 is a partial cutaway perspective view of the debris removalsystem shown in FIG. 3.

FIG. 5 is an exploded partial view of the hand-held power tool anddebris removal system shown in FIG. 3.

FIG. 6 is a partial cutaway perspective view of a portion of the debrisremoval system shown in FIG. 3.

FIG. 7 is a partial perspective view of the hand-held power tool shownin FIGS. 1 and 2 without a depth guide.

FIG. 8 is a perspective view of the portion of the hand-held power toolshown in FIG. 7 with a mounting assembly system of the debris removalsystem according to an exemplary embodiment.

FIG. 9 is a cross-sectional view of the mounting assembly system takenalong line 9-9 of FIG. 8.

FIG. 10 is a perspective view of the portion of the hand-held power toolshown in FIG. 8 with a pressure differential generating element of thedebris removal system according to an exemplary embodiment.

FIG. 11 is a perspective view of the portion of the hand-held power toolshown in FIG. 10 with a housing of the debris removal system accordingto an exemplary embodiment.

FIG. 12 is a perspective view of the portion of the hand-held power toolshown in FIG. 11 with a depth guide according to an exemplaryembodiment.

FIG. 13 is a partial cutaway perspective view of a debris removal systemaccording to another exemplary embodiment.

FIG. 14 is a bottom perspective view of a depth guide attachmentaccording to an exemplary embodiment.

FIG. 15 is a top perspective view of the depth guide attachment shown inFIG. 14.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring generally to the FIGURES, an exemplary embodiment of a powertool, shown as a rotary cutting tool 100, is provided. Nonexclusiveexamples of rotary cutting tools are shown and described in U.S. Pat.Nos. 6,443,676, 6,048,260; 5,902,080; D439,484; and D439,122 and U.S.Pat. No. 6,443,675, each of which are expressly incorporated herein byreference and which are assigned to an affiliated company of RobertBosch Tool Corporation. It should be noted that while the rotary cutouttool shown and described herein and in the patents and applicationsincorporated by reference are manufactured and sold by Robert Bosch ToolCorporation, tools of other makes and models may also be used inconjunction with the inventions described herein.

An exemplary embodiment relates to a debris removal attachment for usewith a hand-held power tool. The attachment includes an extension shaft,a first impeller coupled to the extension shaft, and a housing providedadjacent the first impeller. The rotation of the first impeller isconfigured to generate a pressure differential sufficient to draw debrisinto the housing.

Another exemplary embodiment relates to a hand-held power tool forcutting a workpiece. The hand-held power tool includes a motor housinghaving a motor provided therein, an output shaft coupled to the motor,and a debris removal system. The debris removal system includes anextension shaft detachably coupled to the output shaft, a first impellercoupled to the extension shaft, and a housing substantially disposedabout the first impeller. The rotation of the first impeller isconfigured to generate a pressure differential sufficient to draw debrisinto the debris removal system.

Referring to FIG. 1, the rotary cutting tool 100 generally includes acasing or housing 110, a motor (not shown), an output shaft (not shown)coupled to the motor and configured for rotational movement, and adevice or mechanism 150 for securing a tool bit 154 to the output shaft.According to the embodiment illustrated, the mechanism 150 for securingthe tool bit 154 to the output shaft of the motor is a collet (notshown) having a collet nut 152. The housing 110 is made of anelectrically insulating material, such as hard plastic and may be formedas two or more sections (e.g., first and second clamshell halves, etc.)which are joined together to form the housing 110 in a suitable manner,such as using mechanical fasteners, an adhesive, welding, or acombination thereof.

According to the embodiment illustrated, the housing 110 is generallycylindrical in shape, and is sized so that a typical user may supportthe rotary cutting tool 100 by grasping the housing 110. Optionally, therotary cutting tool 100 may include one or more handles 120 coupled tothe housing 110 to allow for the rotary cutting tool 100 to be graspedmore firmly and comfortably by a user, to provide greater control of therotary cutting tool 100 during operation, and/or to provide for moreaccurate cuts with less operator fatigue. Handle 120 is shown as beingaligned substantially parallel with the longitudinal axis of the housing110, but alternatively may be supported in any of a number of positions.

For some applications it may be desirable that the handle 120 bedetached. For example, for making cuts in close quarters or obstructedareas, the handle 120 may become an obstruction, and actually interferewith the making of accurate cuts. Thus, it is desirable to provide bothfor securely attaching the handle 120 to the rotary cutting tool 100when needed and for easily detaching the handle 120 from the rotarycutting tool 100 when its use would interfere with operation of thetool. According to the various alternative embodiments, the handle 120(if provided) may be permanently coupled to the housing 110 (e.g., bybeing integrally formed with the housing 110, etc.).

According to the embodiment illustrated, the motor is enclosed withinthe housing 110. The motor receives electrical power from a battery pack130 detachably supported by the housing 110. In this manner, the rotarycutting tool is a “cordless” power tool. A member or element 132 isprovided to allow the battery pack 130 to be removed when the member 132is depressed. According to an exemplary embodiment, the battery pack 130includes one or more rechargeable batteries and has a fully chargedvoltage between 12 and 24 volts. The battery pack 130 may include anysuitable type of batteries, such as nickel-metal hydride or lithium-ionbatteries. According to various alternative embodiments, the tool 100may be a “corded” or hard-wired power tool wherein the motor receiveselectrical power through an electrical cord coupled to an energy supply.According to other various alternative embodiments, the tool may beconfigured to be interchangeable between a cordless and a corded powertool.

Preferably, the rotary cutting tool 100 has an on/off switch forselectively energizing the motor. According to the embodimentillustrated, the motor is turned on and off by a power on/off switch140. For example, the switch 140 is pulled away from the housing 110 toactivate the motor and moved towards the housing 110 to deactivate themotor. According to other exemplary embodiments, the switch 140 may beotherwise configured. The motor may be configured to operate at a singlespeed (e.g., a speed between approximately 15,000 and 30,000 rpm) or anumber of speeds (e.g., speeds of 15,000 rpm, 20,000 rpm, and 30,000rpm). In a case where the motor is capable of operating at multiplespeeds, the switch 140 may include multiple positions corresponding tothe desired motor speed.

When energized, the motor of the rotary cutting tool 100 drives anoutput shaft (e.g., motor shaft, drive shaft, etc.). The output shaft ofthe tool 100 is generally coaxial with a central axis of the housing110. A cooling fan (not shown), located within the housing 110 aroundthe location where the motor shaft emerges from the housing 110 (i.e.,an operating end 170), is preferably attached to the output shaft. Asthe output shaft is driven by the motor, the cooling fan is rotated todraw air through the housing 110 and across the motor. For this purpose,intake air vents 172 and exhaust air vents 174 are provided in thehousing 110. According to the embodiment illustrated, intake air vents172 are formed on the side of the housing 110 at the operating end 170of the housing 110 and opposite the exhaust air vents 174. Relativelycool air is drawn by the cooling fan into the housing 110 through theair intake vents 172 to cool the motor, with relatively warm airexhausted from the housing 110 through the exhaust air vents 174.

An end of the motor shaft extends from one end of the housing 110 alongthe central axis thereof. A device or mechanism 150 is provided forsecuring a cutting accessory (e.g., a helical cutting tool bit or otheraccessory) to the motor shaft. The mechanism 150 includes a collet (notshown) and the collet nut 152 for securing a tool bit 154 to the motorshaft of the rotary cutting tool 100. According to an exemplaryembodiment, the tool bit 154 includes a cutting edge wrapped around theaxis of the bit in a helix or spiral. This cutting edge is designed suchthat the tool bit 154, when rotated at high speed, will cut through aworkpiece in a direction perpendicular to the axis of the bit.

To secure the tool bit 154 to the output shaft, a shank of the tool bitis inserted into a central aperture of the collet, after which thecollet nut 152 is tightened. A shaft lock 156 is used to preventrotation of the output shaft when the collet nut 152 is being loosenedand tightened. As the collet nut 152 is tightened down on the threadedend of the output shaft, the collet is compressed within the collet nut152 between a partially closed end of the collet nut 152 and the outputshaft. The collet is slotted and has tapered ends such that when thecollet is compressed between the collet nut 152 and the output shaft,the collet is compressed radially, causing the central aperture of thecollet to close tightly around the shank of the tool bit. To remove thetool bit from the output shaft, the collet nut 152 is loosened until thetool bit can be removed easily from the central aperture of the collet.

To set the depth of cut to be made by the rotary cutting tool 100, anadjustable depth guide assembly 160 may be provided. The depth guide 160is attached to the housing 110 at the operating end 170. As shown inFIG. 1, a depth guide bracket 162 is selectively attachable to thehousing 110, and may be attached to the housing 110 in any suitablemanner. For example, the depth guide bracket 162 may be formed to have asplit collar structure and a cam closing mechanism 164 (e.g., anover-center latch). The depth guide bracket 162 may be operated to closethe collar tight around the end of the housing 110, and which may beoperated to loosen the collar to remove the depth guide bracket 162 fromthe housing 110.

The depth of cut of the rotary cutting tool 100 may be set by moving anextending portion 166 of the depth guide 160 in an axial directionrelative to the bracket 162. A locking mechanism may then be used tolock the extending portion 166 in a fixed position relative to thebracket 162 to securely fix the depth guide 160 in place. The lockingmechanism may be implemented as a cam lever, as a threaded nut or ascrew, or as any other suitable type of device or mechanism.

As a workpiece is cut using the rotary cutting tool 100, cutting debris(e.g., particles, dust, sawdust, chips, etc.) may deposit and build upon the workpiece surface at or near the point of the cut and/or maybecome airborne and disperse throughout the working environment. Suchdebris may interfere with the visibility of the user trying to controlthe rotary cutting tool 100 to make a precise cut of a desired shape.For example, debris deposited on the workpiece may obscure a cut linemarked on the workpiece. Simply dispersing (e.g., blowing, etc.) suchdebris throughout the working environment would only increase the amountof cleanup required after the cutting is completed. To collect orotherwise contain at least a portion of the cutting debris generated bythe rotary cutting tool 100, a vacuum system is added to the tool.

Referring to FIG. 3, an exemplary embodiment of the vacuum system,referred to as a debris removal system 200, and components thereof isshown coupled to the rotary cutting tool 100. The debris removal system200 generally includes a pressure differential generating elementconfigured to draw debris away from a workpiece, a drive element foroperatively coupling the pressure differential generating element to thepower tool, a cover disposed at least partially about the pressuredifferential generating element for assisting in maintaining thepressure differential created by the pressure differential generatingelement, a coupling element for securing the debris removal system 200to the power tool, and a sealing element for reducing the amount debrisdrawn into a housing of the power tool. Optionally, the debris removalsystem 200 may further include a debris collection element suitable forcollecting debris drawn by the pressure differential generating element.

The debris removal system 200 is shown in the form of an attachment(e.g., an adapter, module, add-on feature, optional component, etc.)that may be securely coupled to the rotary cutting tool 100 in arelatively simple and efficient manner by a user, and removed from therotary cutting tool 100 in a similar manner when its use is no longerdesired. Further, the debris removal system 200 is preferably driven(i.e., powered) by an already existing output shaft of the rotarycutting tool 100. The pressure differential generating element of thedebris removal system 200 is self-supporting (meaning that an externalor standalone vacuum supply is not required to generate the pressuredifferential used to draw debris from the workpiece). However, incertain applications, it may be desirable to make use of an external orstandalone vacuum supply.

It should be understood that, although the debris removal system 200will be described in detail herein with reference to the rotary cuttingtool 100, the debris removal system 200 may be applied to, and findutility in, other types of power tools (e.g., hand-held power tools,etc.) as well. For example, the debris removal system 200 may besuitable for use with routers, drills, reciprocating saws, grinders,jigsaws, sanders, or any other power tool. It should further beunderstood that while the debris removal system 200 will be described indetail herein as being a detachable system (i.e., an attachment),according to various other exemplary embodiments, the debris removalsystem 200 may be integrally formed with or otherwise configured to bepermanently coupled to a power tool.

The debris removal system 200 is configured to remove (and optionallycollect) cutting debris generated adjacent to the workpiece during theoperation of the rotary cutting tool 100. The debris removal system 200removes debris by generating an area of lower pressure (i.e., a vacuum)adjacent to the workpiece thereby causing air and at least a portion ofthe debris to be drawn away from the workpiece. While the debris removalsystem 200 is shown as an attachment (e.g., adapter, module, add-onfeature, etc.) intended to be selectively added and detached from therotary cutting tool 100, those skilled in the art who review thisdisclosure will readily appreciate that the debris removal system 200may be integrated with the rotary cutting tool 100 in a manner such thatthe debris removal system 200 will be permanently coupled to the rotarycutting tool 100.

Referring to FIGS. 4 and 5, the debris removal system 200 generallyincludes a pressure differential generating element (shown as a fanassembly 202), a drive element (shown as an output shaft extension 220)adapted to transfer rotational movement of the output shaft of the powertool to the pressure differential generating element, a cover element(shown as a housing 240) disposed at least partially about the pressuredifferential generating element, a coupling element (shown as a mountingassembly 270) for securing the debris removal system 200 to the rotarypower tool 100, a sealing element (shown as a sealing system 300)adapted to reduce the amount debris drawn into the motor housing of therotary cutting tool 100, and a debris collection element (shown as adebris receptacle or canister 320) suitable for collecting at least someof the debris removed by the pressure differential generating element.

Referring to FIG. 6, the fan assembly 202 is shown as generallycomprising a first impeller 204, an annular hub 206, and a substantiallyplanar portion 208. Rotation of first impeller 204 functions as a pumpcreating an area of lower pressure adjacent to the workpiece. Thisnegative pressure differential created by rotation of the first impeller204 causes air to be drawn from around the workpiece into the housing240 (e.g., as shown in FIG. 5). At least a portion of the debris iscarried away by the air that is drawn by the first impeller 204 therebyfacilitating its removal from the workpiece and/or the rotary cuttingtool 100.

The first impeller 204 is shown as having a plurality of fan blades 210extending outwardly in a radial direction from the annular hub 206 andin the axial direction from the substantially planar portion 208. Thefan blades 210 have a radius that is shown as changing from a relativelylarger radius near the annular hub 206 to a relatively smaller radiusnear the substantially planar portion 208. The fan blades 210 arefurther shown as bending or curving as they extend outwardly in a radialdirection from the annular hub 206. The configuration of the fan blades210 is intended to assist in drawing air from around the workpiece intothe housing 240. The fan blades 210 may be generally perpendicular tothe substantially planar portion 208, or alternatively, the fan blades210 may be tilted and provided at an angle relative to the substantiallyplanar portion 208. According to various other exemplary embodiments,the fan blades 210 may have any of a number of configurations suitablefor drawing air from around the workpiece.

The annular hub 206 is shown in the form of a sleeve having an innersurface 212 defining a bore 214 (e.g., as shown in FIG. 5). The bore 214has a diameter sufficiently sized to be disposed about the output shaftextension 220 and facilitate in coupling the fan assembly 202 to theoutput shaft extension 220. Thus, the fan assembly 202 is generallyconcentrically aligned with the central longitudinal axis of the rotarycutting tool 100. Coupling the fan assembly 202 to the output shaftextension 220 enables the debris removal system 200 to be driven (i.e.,powered) by the rotary cutting tool 100. More specifically, coupling thefan assembly 202 to the output shaft extension 220 allows the fanassembly 202 to rotate in response to the rotation of the output shaftextension 220 (and to that of the output shaft). As such, the outputshaft extension 220 and the fan assembly 202 will operate atsubstantially the same speed. As mentioned above, the output shaft ofthe rotary cutting tool 100 (and thus the output shaft extension 220 andthe fan assembly 202) may operate at speeds up to 30,000 rpm.

The fan assembly 202 may be coupled to the output shaft extension 220using any of a variety of suitable techniques. For example, the innersurface 212 of the hub 206 may frictionally engage (e.g., press-fit,snap-fit, axially interfering fit, etc.) the output shaft extension 220as the output shaft extension 220 is inserted into the bore 214.Alternatively, the fan assembly 202 may be coupled to the output shaftextension 220 using one or more mechanical fasteners (e.g., set screws,locking pins, etc.), a welding process (e.g., ultrasonic welding, etc.),an adhesive, or any other suitable technique. According to a furtheralternative embodiment, the fan assembly 202 may be integrally formedwith the output shaft extension 220 to provide a unitary one-piecemember.

The substantially planar portion 208 may provide support for the fanblades 210 and/or may assist in guiding debris that is drawn into thedebris removal system 200. The substantially planar portion 208 is shownas being relatively flat and extending in a substantially radialdirection (relative to the output shaft extension 220), but according tothe various alternative embodiments, the substantially planar portion208 may have one or more portions that extend linearly or curvilinearlyin both an axial and/or radial direction. According to the embodimentillustrated, a projection or raised lip 211 is provided about the innerperiphery of the substantially planar portion 208. The raised lip 211may provide additional rigidity to the fan assembly 202 by reducingdeflection of the substantially planar portion during rotation of thefirst impeller 204, and/or may further assist in guiding debris that isdrawn into the debris removal system 200.

Referring to FIG. 4, to transfer the rotational movement of the outputshaft of the rotary cutting tool 100 to the fan assembly 202 and/or thesealing system 300, the output shaft extension 220 is provided. Theoutput shaft extension 220 is shown as a cylindrical member extendingbetween a first end 222 and a second end 224. The length of the outputshaft extension 220 may vary depending on the other components of thedebris removal system 200. Threads 226 are provided on an inner surfaceof the first end 222 for coupling the output shaft extension 220 to thethreaded end of the output shaft of the rotary cutting tool 100. Forsuch an embodiment, the collet nut 152 is removed from the threaded endof the output shaft and replaced with the output shaft extension 220.According to various alternative embodiments, the first end 222 may havea structure other than the threads 226 which cooperate with acorresponding structure on the output shaft of the rotary cutting tool100 for securing the motor shaft extension 220 to the output shaft ofthe rotary cutting tool 100. According to a further alternativeembodiment, the first end 222 may have a structure configured to becoupled to the collet nut 152.

The second end 224 of the output shaft extension 220 is configured toreceive a device or mechanism 228 capable of securing a cuttingaccessory to the output shaft extension 220. According to the embodimentillustrated, the mechanism 228 includes a collet 230 and a collet nut232. The collet nut 232 may be the same collet nut 152 shown in FIG. 1,or alternatively, may be particularly adapted to couple to the secondend 224 of the output shaft extension 220.

To assist in maintaining the pressure differential generated by therotation of the fan assembly 202 and/or to assist in defining the flowpath or passage for debris drawn away from the workpiece, the housing240 is provided (e.g., as shown in FIG. 4). The housing 240 includes acylindrical portion 242 defining a cavity or chamber 244 configured toreceive the fan assembly 202. The housing 240 extends between a firstend 246 and a second end 248 and is preferably coaxially aligned withthe central axis of the rotary cutting tool 100. Threads 250 areprovided on an indented outer surface of the first end 246. The threads250 are provided to detachably secure the housing 240 to the mountingsystem 270. According to various other exemplary embodiments, thehousing 240 may be coupled to the mounting system 270 using any of avariety of suitable techniques. For example, cylindrical portion 242 mayinclude an inner detent or a raised ring to allow it to be snap-fit to acorresponding structure on the mounting system 270. According to afurther alternative embodiment, the housing 240 may be coupled directlyto the housing 110 of the rotary cutting tool 100.

The second end 248 of the housing 240 includes an indented cylindricalportion providing a surface to which a tool accessory may be coupled.For example, the second end 248 may be configured to receive a depthguide (e.g., the depth guide 160 shown in FIG. 5, the depth guide 1600shown in FIGS. 14-15, etc.). According to various alternativeembodiments, the second end 248 may include a structure (e.g. threads, agroove, a rib, etc.) for assisting in coupling a tool accessory to thehousing 240.

The housing 240 may be made of any of a variety of suitable materials,such as hard plastic similar to that used for the housing 110 of therotary cutting tool 100. The housing 240 may be formed of such amaterial in two or more complementary members (e.g., first and secondclamshells halves, etc.) by a suitable molding process. The two or moremembers are then joined together to form the complete housing 240. Thetwo or more members may be coupled together in any suitable technique,for example, using a welding process or an adhesive. The two or moremembers are preferably coupled together, using screws or another type ofmechanical fastener. For this purpose, screw holes 252 may be formed inthe housing 240. According to various alternative embodiments, thehousing 240 may be formed as a one-piece member.

Referring further to FIG. 4, the chamber 244 defined by the housing 240is sufficiently sized to receive the fan assembly 202 so that the firstimpeller 204 of the fan assembly 202 can rotate in a generallyunobstructed manner therein. While the first impeller 204 requires acertain amount of clearance between the cylindrical portion 242 and thefan blades 210, according to the embodiment illustrated, any space orgap between the fan blades 210 and the cylindrical portion 242 isminimized to assist in maintaining the pressure differential generatedby the fan assembly 202, and/or to reduce the overall size of the debrisremoval system 200. By way of example, a gap ranging betweenapproximately 1 millimeter and approximately 2.5 millimeters may beprovided between the first impeller 204 and the cylindrical portion 242.According to various other exemplary embodiments, a portion of the firstimpeller 204 may be configured to engage (e.g., brush against, etc.) thecylindrical portion 242 as the first impeller 204 rotates. For example,a bearing surface may be provided between the first impeller 204 and thecylindrical portion 242.

The chamber 244 is in fluid communication with at least one exhaust portor conduit (shown as an exhaust duct 254). The exhaust duct 254 providesan opening through which debris may exit the housing 240 after beingdrawn by the rotation of the fan assembly 202. According to theembodiment illustrated, a single exhaust duct 254 is provided. Theexhaust duct 254 is preferably sized large enough to prevent or minimizethe exhaust duct 254 from becoming clogged with debris.

The debris removal system 200 is shown as including the canister 320which is configured to collect debris drawn by the fan assembly 202 andpassed through the exhaust duct 254. The canister 320, shown as beingsupported at an open end of the exhaust duct 254, may be detachably orfixedly coupled at the exhaust duct 254. The canister 320 may be coupledat the exhaust duct 254 by a friction fit, interference fit, mechanicalfastener (e.g., clip, screw, rivet, etc.), adhesive, welding or anyother known or otherwise suitable technique. Detachably coupling thecanister 320 at the exhaust duct 254 may allow the entire canister 320to be selectively removed from the debris removal system 200 and/or therotary cutting tool 100. Being able to selectively remove the canister320 may allow a user to more easily empty debris collected in thecanister 320 and/or may provide a user with a tool having increasedflexibility. For example, if a user is operating a power tool in alimited space, it may be desirable to use the debris removal system 200without the canister 320.

Preferably, the canister 320 will have sufficient capacity to collectdebris generated during several cutting operations. Referring again toFIG. 5, the canister 320 is shown as being in the form of a relativelyrigid housing having an inlet 322 configured to be in communication withthe exhaust duct 254 and one or more exhaust vents 324 for allowing airto pass through the system. Preferably, a filter (e.g., a pad, bag,screen, etc.) is provided within the canister 320 to trap debris whileallowing air to pass through the exhaust vents 324. Those skilled in theart will appreciate that the canister 320 may be replaced with anysuitable mechanism for collecting debris (e.g., a fine mesh bag, etc.).Further, the debris collection element may be substantially near therotary cutting tool 100 (as shown), or alternatively, may be provided ata distance from the tool and coupled thereto via a suitable conduit(e.g., hose, tube, pipe, etc.). According to a further alternativeembodiment, an external or stand-alone vacuum (not shown) may be coupledto the exhaust duct 254 for collecting debris and/or to assist in theremoval of the cutting debris from the workpiece and/or the rotarycutting tool 100.

Optionally, a seal (not shown) may be employed to seal the interface orjoint between the canister 320 and the exhaust duct 254 of the housing240. According to an exemplary embodiment, the seal may be a gasketformed of a resilient material, such as rubber, and designed to becompressed between the canister 320 and the exhaust duct 254. Accordingto various alternative embodiments, the seal may be provided by anyknown or otherwise suitable technique for providing a seal. Providing aseal between the exhaust duct 254 and the canister 320 may reduce thelikelihood that an opening (e.g., a gap, etc.) will exist between theexhaust duct 254 and the canister 320. Such an opening, if present, maycause an undesired change of pressure within the system (e.g., a hose ofthe vacuum, etc.) and/or provide an unintended escape path for debris.

According to an alternative embodiment, the debris removal system 200may be configured without a debris collection element. For example, forcertain power tools and/or certain applications a user may not beconcerned about airborne debris and may only be interested in removingdebris from around the workpiece. For such an embodiment, the exhaustduct 254 may be provided at an angle for directing debris away from theuser and/or the rotary cutting tool 100.

Referring to FIGS. 5-9, the debris removal system 200 is coupled to therotary cutting tool 100 by the mounting assembly 270. Preferably, themounting assembly 270 is configured to detachably couple the debrisremoval system 200 to the rotary cutting tool 100 so that a user canselectively add or remove the debris removal system 200 depending on theparticular application. The mounting system 270 is shown as including afirst member or a mounting ring 272 and second member or a compressionring 274. The mounting ring 272 and the compression ring 274 cooperateto facilitate the securement of the debris removal system 200 to theoperating end 170 of the rotary cutting tool 100.

The mounting ring 272 includes a cylindrical portion 276 extendingbetween a first end 278 configured to be coupled to the operating end170 of the rotating cutting tool 100 (e.g., a tool neck 171, etc.) and asecond end 280 configured to be coupled to the housing 240 of the debrisremoval system 200. The first end 278 defines an aperture having adiameter corresponding to the diameter of the tool neck 171. Accordingto various alternative embodiments, the first end 278 of the mountingring 272 may have other configurations than that shown to match theparticular power tool for which the debris removal system is to be usedwith. According to further alternative embodiments, the first end 278 ofthe mounting ring 272 may include an adjustable member (e.g., a clamp,etc.) for allowing the debris removal system 200 to be used with powertools differing in size and/or shape.

Referring to FIG. 9, the first end 278 is shown as including an upwardlyextending annular projection 284 configured to snap over the tool neck171. A lip or rib 285 is provided adjacent an end of the projection 284for engaging a corresponding structure (shown as a groove 173) on thetool neck 171. Engagement of the rib 285 into the groove 173 assists insecuring the mounting ring 272 to the tool neck 171. Preferably, theprojection 284 is a resilient member configured to flex when a radialforce is exerted thereto.

The first end 278 of the mounting ring 272 is also shown as forming aseal with the tool neck 171. In particular, the seal is provided betweena shoulder portion 175 of the tool neck 171 and an end surface of thefirst end 278. The shoulder portion 175 of the tool neck 171 is shown asbeing a substantially radial surface (relative to the output shaft), butalternatively may be an angled or sloped surface. According to anexemplary embodiment, the end surface of the first end 278 is formed ofa resilient material configured to form a compression seal when the rib285 engages the groove 173. The resilient member may be integrallymolded with the mounting ring 272, or alternatively may be provided as aseparate component that is attached to the mounting ring 272 and/or thetool neck 171.

According to an exemplary embodiment, threads 282 are provided on aninner surface of the second end 280 of the mounting ring 272 fordetachably coupling the mounting assembly 270 to the threads 250 of thehousing 240 (e.g., as shown in FIG. 4). According to various alternativeembodiments, the second end 280 may include any of a number ofmechanisms for coupling the mounting assembly 270 to the housing 240.

The mounting assembly 270 further includes the compression ring 274. Thecompression ring 274 is an annular member having a substantially planarportion 286, a first annular projection 288 extending outwardly from afirst surface of the substantially planar portion 286, and one or moreannular sealing projections 290 (shown as a pair of sealing projections290) extending outwardly from a second surface of the substantiallyplanar portion 286. The compression ring 274 is concentrically alignedwith the mounting ring 272 with the first annular projection 288 beingdisposed outside of the projection 284 of the mounting ring 272 (i.e.,provided on a side opposite the tool neck 171). A first or free end ofthe first annular projection 288 is shown as having an inclined surfaceconfigured to engage a corresponding surface on the projection 284. Whenthe housing 240 is threaded onto the mounting ring 272, the housing 240will exert a force on the compression ring 274 which will in turn causethe compression ring 274 to exert a force on the projection 284 therebyurging the rib 285 into the groove 173.

According to various other exemplary embodiments, any number of suitablemounting assemblies may be employed to couple the housing 240 to therotary cutting tool 100. For example, the mounting ring 272 and thecompression ring 274 may be integrally formed as a single, one-pieceunitary body. According to a further alternative embodiment, themounting assembly may be configured to permanently couple the debrisremoval system 200 to the rotary cutting tool 100.

Referring now to FIG. 6, an exemplary embodiment of the sealing system300 is shown. The sealing system 300 is provided in an effort to preventdebris from being drawn into the housing 110 of the rotary cutting tool100 and/or to reduce the amount of debris realized by a front bearing(not shown) of the rotary cutting tool 100. Reducing the amount ofdebris drawn into the housing 110 may prolong the operating life of therotary cutting tool 100 by reducing the amount of build-up that mayoccur on the motor from debris entering the housing 110. Similarly,reducing the amount of debris reaching the front bearing may allow theoutput shaft to continue to rotate at a consistent speed. The sealingsystem 300 provides a seal between the output shaft of the rotarycutting tool 100 and the debris removal system 200. To accommodate thedynamic nature of the sealing location between the output shaft and thedebris removal system 200 (e.g., the output shaft of the rotary cuttingtool 100 can operate in excess of 30,000 rpm), the sealing system 300 ispreferably in the form of a non-contact seal (i.e., a seal that does notphysically contact the rotating output shaft).

According to the embodiment illustrated, the sealing system 300comprises a first seal 302 and a second seal 304. The first seal 302 isconfigured to generate an air stream or flow for pushing or deflectingat least a portion of the debris away from the tool 100, while thesecond seal 304 is configured to deter debris from reaching the frontbearing and/or the housing 110 by providing a labyrinth seal comprisingat least one barrier for restricting (e.g., selectively altering, etc.)a passage leading to the interface or joint between the output shaft andthe output shaft extension 220. According to various other exemplaryembodiments, the debris removal system 200 may include only one seal(e.g., the first seal 302 or the second seal 304, etc.), or may includeany number of seals greater than two.

The first seal 302 (e.g., a deflection seal, etc.) is shown as a fanassembly generally comprising a second impeller 306 and a substantiallyplanar portion 308. The second impeller 306 is shown as having aplurality of fan blades 310 outwardly extending in a radial directionfrom an annular hub 312 and in axial direction from the substantiallyplanar portion 308. The fan blades 310 are shown as being generallyperpendicular to the substantially planar portion 308. The substantiallyplanar portion 308 divides the first impeller 204 from the secondimpeller 306 and may assist in preventing debris drawn into the housing240 from reaching the operating end 170 of the rotary cutting tool 100.

The second seal 304 provides additional sealing protection byfunctioning as a back-up seal for debris getting past the first seal302. The second seal 304 is in the form of a labyrinth seal having oneor more barriers (e.g., projections, etc.). According to the embodimentillustrated, the second seal 304 comprises one or more annularprojections 314 (e.g. barriers, etc.) extending from the second impeller306 which cooperate with the sealing projections 290 extending from thecompression ring 274 to form the labyrinth seal. As shown, the annularprojection 314 is concentrically aligned between the sealing projections290. When assembled, a gap is provided between a free end of the annularprojection 314 and the substantially planar portion 286 of thecompression ring 274. Similarly, gaps are provided between free ends ofthe sealing projections 290 and the substantially planar portion 308 ofthe second impeller 306. The size of such gaps are minimized. These gapsdefine a passage (such as, e.g., represented by arrow 301 in FIG. 6)through which debris would have to follow in order to reach theoperating end 170 of the rotary cutting tool 100. According to variousother exemplary embodiments, the second seal 304 may include any numberof barriers, aligned at any of a variety of orientations, forrestricting the passage leading to the joint between the output shaftand the output shaft extension 220.

It should be noted that, the first impeller 204 may be integrally formedwith the second impeller 306 or may be provided as a separate component.According to the embodiment illustrated, the first impeller 204 and thesecond impeller 306 are separate components configured to be coupledtogether in a manner such that the rotation of the first impeller 204coincides with the rotation of the second impeller 306.

In some applications, a user may wish to detach the debris removalsystem 200 from the rotary cutting tool 100. For example, when makingcuts in close quarters or obstructed areas, the added length and/orwidth of the debris removal system 200 may become an obstruction, andactually interfere with the making of accurate cuts. Further, whenrepeatedly making overhead cuts, the added weight of the debris removalsystem 200 may be undesirable to a user. Thus, it is desirable toprovide for both securely coupling the debris removal system 200 to therotary cutting tool 100 and for easily detaching the debris removalsystem 200 from the rotary cutting tool 100.

With reference to FIGS. 7 through 12, the following methods may beemployed to add or remove the debris removal system 200 relative to therotary cutting tool 100. To add the debris removal system 200 to therotary cutting tool 100, a depth guide (if being employed) isselectively removed from the operating end 170 of the rotary cuttingtool 100, and the collet nut 152 is removed from the output shaft. Themounting ring 272 of the mounting assembly 270 can then be disposed over(e.g. snapped over, etc.) the operating end 170 such that the rib 285 ofthe projection 284 extending from the mounting ring 272 is substantiallyaligned with and engages the groove 173 formed in the tool neck 171. Thecompression ring 274 can then be disposed about the tool neck 171 suchthat the first annular projection 288 is provided on the outside of theprojection 284 of the mounting ring 272. Alternatively, the mountingring 272 and the compression ring 274 may be coupled together andinstalled on the rotary cutting tool as a single unit.

The output shaft extension 220 may then be coupled to the output shaftby rotating the output shaft extension 220 about the threads of theoutput shaft. The second impeller 306 and the first impeller 204 canthen be disposed about the output shaft extension 220. Alternatively,the second impeller 306, the first impeller 204, and the output shaftextension 220 may be coupled together and installed on the rotarycutting tool 100 as a single unit.

The housing 240 may then be threaded into the mounting ring 272. As thehousing 240 is threaded into the mounting ring 272, the compression ring274 forces the mounting ring 272 into engagement with the tool neck 171.At this point, the mechanism 228 may be coupled to the second end 224 ofthe output shaft extension 220, and/or the depth guide 160 may be added.To remove the debris removal system 200, the above-described steps maybe reversed.

Referring to FIG. 13, another exemplary embodiment of a debris removalsystem 1200 is shown. For brevity, the description of the debris removalsystem 1200 will be generally limited to its differences relative to thedebris removal system 200 described above. For convenience, elements ofthe debris removal system 1200 that are substantially similar tocorresponding elements of the debris removal system 200 will beidentified by the same reference numerals but preceded by a “1.”

The debris removal system 1200 differs from the debris removal system200 in that the sealing system 1300 does not make use of the secondimpeller 306. Without the second impeller 306, the sealing system 1300does not employ a deflection seal or a labyrinth seal. Rather, thesealing system 1300 comprises a bearing 500 disposed about the outputshaft extension 1220. The bearing 500 is shown as being disposed aboutthe output shaft extension 1220 near the interface with the outputshaft. According to other embodiments, the bearing 500 may be disposedabout the output shaft extension 1220 in a different location.

As indicated earlier, it may be desirable to provide an attachment thata user may use to set the depth of the cut to be made by the rotarycutting tool 100 (i.e., a depth guide). However, it has been discoveredthat in certain applications use of a depth guide in combination withthe debris removal system 200 reduces the pressure differential (i.e.,suction) generated by the debris removal system 200 around the workpiecethereby reducing the effectiveness and/or efficiency of the debrisremoval system 200. The reduction of suction is caused at least in partby the general openness of the depth guide. For example, the depth guide160 illustrated in FIG. 1 intentionally includes a generally openstructure so that visibility by a user around the operating head of thepower tool is increased.

With reference to FIGS. 14 and 15, another exemplary embodiment of adepth guide suitable for use with a power tool utilizing a vacuum ordebris removal system, such as the debris removal system 200, isprovided. The depth guide, shown as depth guide 1600, is capable ofmaintaining a pressure differential created by the debris removal system200 so that cutting debris can be effectively removed from around thetool bit when a depth guide is being used. According to an exemplaryembodiment, the depth guide 1600 is selectively attachable to the debrisremoval system 200 and/or the housing 110 of the rotary cutting tool100.

It should be noted that while the depth guide 1600 is described as beingcoupled to the debris removal system 200, the depth guide 1600 may alsobe coupled directly to the rotary cutting tool 100 in the event that adebris removal system is not used.

The depth guide 1600 generally includes an outer portion (e.g., body,etc.), shown as a base 1602 and an inner portion, shown as an insert1604. The insert 1604 is shown as being a separate member that iscoupled relative to the base 1602, but alternatively the base 1602 andthe insert 1604 may be provided as an integrally formed one-pieceunitary body. The base 1602 and the insert 1604 cooperate to define asubstantially enclosed passage or chamber between the workpiece and thedebris removal system 200.

The base 1602 is shown as a generally cylindrical member having a topend 1605 (shown in FIG. 15) and a bottom end 1606 (shown in FIG. 14).When the depth guide 1600 is coupled to the debris removal system 200,the top end 1605 is configured to be adjacent to the debris removalsystem 200, while the bottom end 1606 is configured to be placedadjacent to the workpiece during a cutting operation performed by therotary cutting tool.

According to the embodiment illustrated, threads 1608 are provided on aninner surface of the base 1602 for coupling the depth guide 1600 to theoutside of the debris removal system 200. For such an embodiment,complementary threads are disposed on an outer surface of the debrisremoval system 200 (e.g., at second end 248 of housing 240, etc.) toengage the threads 1608. For example, complementary threads may bedisposed on an outer surface of the second end 248 of the housing 240(shown in FIG. 5). The threads 1608 preferably begin at the top end 1605of the base 1602 and extend downward a substantial length of the base1602.

With the engagement of the threads 1608 and the corresponding threads onthe debris removal system 200, the depth of the cut of the rotarycutting tool 100 may be set by rotating the base 1602 relative to thedebris removal system 200. Depending on the direction of rotation,rotation of the base 1602 will cause the base 1602 to move upward ordownward in an axial direction relative to the debris removal system 200thereby setting the depth of cut. For such an embodiment, the accuracyof the depth guide 1600 is dictated, at least in part, by the size ofthe threads 1608. For example, a user is likely to have more controlover the positioning of the depth guide 1600 in the axial direction ifthe thread size of the threads 1608 is a relatively fine thread ratherthan a relatively course thread.

To assist a user in rotating the base 1602, an outer surface of the base1602 includes a configuration intended to promote gripping of the base1602 either by a hand of the user or by a suitable tool (e.g., wrench,clamp, etc.). According to an exemplary embodiment, the outer surface ofthe base 1602 includes one or more raised projections intended tosimplify the rotation of the base 1602. According to the embodimentillustrated, the base 1602 includes a series of spaced-apart projections1610 extending in a substantially axial direction around the peripheryof the outer surface of the base 1602. The projections 1610 are shown asbeing substantially rectangular in shape, but alternatively may beprovided in any of a variety of suitable shapes (e.g., spherical, etc.).

Attachment of the depth guide 1600 to the debris removal system 200 isnot limited to a threaded connection. According to various alternativeembodiments, the depth guide 1600 may be attached to the debris removalsystem 200 in any suitable manner. For example, the base 1602 of thedepth guide 1600 may be formed to have a split collar structure and acam closing mechanism (e.g., an over-center latch) which is operated toclose the collar tight around the end of the debris removal system 200,and which may be operated to loosen the collar to remove the depth guide1600 from the debris removal system 200.

Referring to FIG. 14 in particular, the bottom end 1606 of the base 1602includes one or more apertures (e.g., cutouts, notches, windows, etc.),shown as openings 1614. The openings 1614 allow air to enter when anegative pressure differential is created by the debris removal system200 and provide visibility around the rotary cutting tool 100 for auser. According to an exemplary embodiment, the openings 1614 are sizedlarge enough to provide sufficient visibility around the rotary cuttingtool 100 for the user. According to the embodiment illustrated, the base1602 is provided with two openings 1614, spaced equidistant from eachother at approximately 180 degrees.

Still referring to FIG. 14, the insert 1604 is provided, at least inpart, to limit the amount of air passing through the openings 1614 inthe base 1602 so that the negative pressure differential created by thedebris removal system 200 is substantially maintained. The insert 1604is shown as a generally cylindrical member that is coupled to the base1602. According to an exemplary embodiment, the insert 1604 is coupledto the base 1602 via an interference fit (e.g., snap-fit, etc.).According to various alternative embodiments, the insert 1604 may becoupled to the base 1602 using a mechanical fastener, friction fit,adhesive, welding, or any other known or suitable technique.

The insert 1604 includes a member (e.g., panel, shield, etc.), shown asdeflector 1616, corresponding to each of the openings 1614. Thedeflectors 1616 are aligned with the openings 1614 and offset radiallyinward therefrom. Each deflector 1616 includes one or more apertures(e.g., cutouts, notches, windows, etc.), shown as an opening 1618. Thesize of the opening 1618 is smaller than the size of the opening 1614from which the deflector 1616 is positioned behind. Utilizing theinwardly offset deflectors 1616 in combination with the openings 1614may improve visibility around the cutting tool since the openings 1614can be sized larger than if no deflector 1616 was provided. According tovarious alternative embodiments, use of the insert 1604 and/or thedeflectors 1616 may be eliminated and the openings 1614 in the base 1602may be optimized so that a user is provided with sufficient visibilitywithout substantially diminishing the suction created by the debrisremoval system 200.

A locking mechanism may be used to lock the base 1602 in a fixedposition relative to the debris removal system 200 to securely fix thedepth guide 1600 in place. According to an exemplary embodiment, thelocking mechanism is a biasing element (e.g., a spring arm, etc.)supported at the debris removal system 200 and configured to releasablyengage the insert 1604 for securing the base 1602 in a fixed position.

Referring to FIG. 15, the insert 1604 is shown as including a pluralityof spaced-apart indentations 1612 with openings facing the inner surfaceof the base 1602. According to the embodiment illustrated, the insert1604 includes four indentations 1612, each one being spaced-apartapproximately 90 degrees from an adjacent indentation 1612. The biasingelement on the debris removal system 200 is configured to releasablyengage one or more of the indentations 1612 to lock or otherwise securethe depth guide 1600 at every 90 degrees of rotation. Use of the biasingelement, in combination with the indentations 1612, is intended toreduce the likelihood that the locking mechanism will loosen orotherwise fail due to the vibration of the rotary cutting tool 100during operation. According to various alternative embodiments, thelocking mechanism may be implemented as a cam lever, as a threaded nutor a screw, or as any other suitable type of device or mechanism.

The debris removal systems 200 and 1200 detailed above advantageouslyprovide debris removal systems that are not required to be connected toa standalone vacuum system. The debris removal systems 200 and 1200 alsoadvantageously provide debris removal systems that are detachable andwhich may be securely coupled to a power tool in a relatively simple andefficient manner. The debris removal systems 200 and 1200 furtheradvantageously provide debris removal systems configured to reduce theamount of debris entering the motor housing of the power tool. Thedebris removal systems 200 and 1200 further advantageously providedebris removal systems that are driven by an already existing outputshaft of the power tool.

It is important to note that the construction and arrangement of thepower tool and debris removal system as shown in the various exemplaryembodiments is illustrative only. Although only a few embodiments of thepresent inventions have been described in detail in this disclosure,those skilled in the art who review this disclosure will readilyappreciate that many modifications are possible (e.g., variations insizes, dimensions, structures, shapes and proportions of the variouselements, values of parameters, mounting arrangements, use of materials,colors, orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter recited in the claims.For example, elements shown as integrally formed may be constructed ofmultiple parts or elements, elements shown as multiple parts may beintegrally formed, the position of elements may be reversed or otherwisevaried, and the nature or number of discrete elements or positions maybe altered or varied. Accordingly, all such modifications are intendedto be included within the scope of the present invention as defined inthe appended claims. The order or sequence of any process or methodsteps may be varied or re-sequenced according to alternativeembodiments. Other substitutions, modifications, changes and omissionsmay be made in the design, operating conditions and arrangement of theexemplary embodiments without departing from the scope of the presentinventions as expressed in the appended claims.

What is claimed is:
 1. A method of using a hand-held power tool having adebris removal attachment, the method comprising: providing a hand-heldpower tool having an output shaft; selectively coupling an extensionshaft to the output shaft, the extension shaft having a first end and asecond end, the first end configured to couple to the output shaft ofthe hand-held power tool, and the second end configured to couple to atool bit; coupling a first impeller to the extension shaft; providing ahousing adjacent the first impeller; and rotating the first impeller togenerate a pressure differential sufficient to draw debris into thehousing.
 2. The method of claim 1, further comprising coupling a secondimpeller to the extension shaft, the rotation of which is configured topush debris away from an interface between the extension shaft and thehand-held power tool.
 3. The method of claim 1, further comprisingcoupling the attachment to a tool neck of the hand-held power tool. 4.The method of claim 3, wherein coupling the attachment to a tool neckcomprises slidably engaging the attachment and the tool neck of thehand-held power tool.
 5. The method of claim 1, further comprisingproviding a labyrinth seal in a pathway between an exterior of thehousing and an interface of the extension shaft and the hand-held powertool, the labyrinth seal having a plurality of spaced apart annularprojections provided for disrupting the pathway.
 6. The method of claim1, further comprising sealing an interface between the extension shaftand the hand-held power tool with at least one bearing disposed aboutthe extension shaft.
 7. A method of using a hand-held power tool havinga debris removal attachment, the method comprising: providing ahand-held power tool comprising: a motor disposed in a motor housing; anoutput shaft coupled to the motor; and providing a debris removalattachment comprising: an extension shaft having a first end and asecond end, the second end configured to couple to a tool bit; a firstimpeller coupled to the extension shaft, the rotation of which isconfigured to generate a pressure differential sufficient to draw debrisinto the debris removal system; a housing substantially disposed aboutthe first impeller; a second impeller coupled to the extension shaft;and a substantially planar member separating the first impeller and thesecond impeller; and detachably coupling the first end of the extensionshaft to the output shaft.
 8. The method of claim 7, further comprisingrotating the second impeller to push debris away from an interfacebetween the extension shaft and the hand-held power tool.
 9. The methodof claim 7, wherein the debris removal attachment further comprises alabyrinth seal having a plurality of spaced apart annular projectionsprovided for disrupting a pathway between an exterior of the housing andan interface of the extension shaft and the hand-held power tool. 10.The method of claim 7, further comprising sealing an interface betweenthe extension shaft and the hand-held power tool with at least onebearing disposed about the extension shaft.
 11. The method of claim 7,further comprising coupling the attachment to a tool neck of thehand-held power tool.
 12. The method of claim 11, wherein coupling theattachment to a tool neck comprises slidably engaging the attachment andthe tool neck of the hand-held power tool.
 13. The method of claim 7,further comprising powering the hand-held power tool with a battery. 14.The method of claim 7, wherein the housing defines an exhaust portthrough which debris drawn into the housing is designed to exit thehousing; and further comprising coupling a receptacle to the exhaustport, the receptacle configured for collecting debris exiting theexhaust port.
 15. The method of claim 7, further comprising selectivelycoupling a depth guide to the debris removal attachment.
 16. A method ofusing a debris removal attachment for a hand-held power tool, the methodcomprising: providing an extension shaft, the extension shaft having afirst end and a second end, the first end configured to couple to anoutput shaft, and the second end configured to couple to a tool bit;coupling a first impeller to the extension shaft; providing a housingadjacent the first impeller; providing a labyrinth seal in a pathwaybetween an exterior of the housing and an interface of the extensionshaft and the output shaft, the labyrinth seal having a plurality ofspaced apart annular projections provided for disrupting the pathway;selectively coupling the first end of the extension shaft to an outputshaft; and rotating the first impeller to generate a pressuredifferential sufficient to draw debris into the housing.
 17. The methodof claim 15, further comprising coupling a second impeller to theextension shaft, the rotation of which is configured to push debris awayfrom an interface between the extension shaft and the output shaft. 18.The method of claim 16, further comprising separating the first impellerand the second impeller with a substantially planar member.
 19. Themethod of claim 17, further comprising permanently coupling the firstimpeller to the second impeller.
 20. The method of claim 18, furthercomprising permanently coupling the extension shaft to the firstimpeller and the second impeller.